One last polling primer: Some pollsters are about to miss badly in Iowa.
Well, my flight is delayed, and I'm sitting here bored off my ass, so why not do one last one of these before voting starts.
As always, my standard disclaimer: I am a Clinton supporter, but I am also a statical analyst in real life. When I do these primers, I do then intending to be nonpartisan.
Anyway, tomorrow is a huge day. Voting starts, we get to finally start awarding delegates and we can take out GDP bickering to a whole new level. But this year, much more than any other recent election, I can say with certainty that some pollsters have done f'd up their models.
At the heart of polling is something very few people are aware exists and even fewer ever get to see. Before any polling is even done, the pollster has to establish something called population parameters. These are what will dictate how samples are weighted and polling is conducted. These include what demographic breakdowns should look like in the final results, and they're unique to each pollster. They're also assumptions, generally based on history and what the pollster "feels" is right.
This year, there are three assumptions that pollsters have to account for that will influence the final results:
% of voters who are women
% of voters who are college aged
% of voters who are first timers
Pollsters have a choice to make: do they use the historical average for these numbers, the numbers from 2008 only or make some other assumption based off their feeling?
Now it should be obvious that historical average favors Clinton, as more women traditionally caucus then men, college aged is 15% or so and first timers are 1/3 the caucus.
2008 favors Bernie, primarily due to first timers accounting for a whopping 60% of turn out.
And own assumptions could be just about anything.
So, what is about to happen is we're putting those who use historical averages to establish parameters versus those who don't to the test. And remember, a margin of error is only valid for the population parameters of that poll, not for the actual real population. Come Tuesday, there will be pollsters frantically changing assumptions going into NH.
= new reply since forum marked as read
Verified voter lists still a strengthener?
At some point behavioral can't be modeled very well. We humans do so many predictably unpredictable things! 
I've enjoyed your posts immensely over the past few months.
Sid
